Oh I lied, they changed the name of the program, it's Amazon First Reads now. I get an email every month letting me know the options for the month. They don't always have something I want so I don't always get it, but it's definitely a fun program!
I mean it's Prime? There's all kinds of perks. I get it for the 2 day shipping, but I also get a free kindle book a month too.
They have a Lord of the Rings universe show in development too I think.